Dayton CX150-8 Coaxial Project

[4thtry]

Greetings all,

I was one of the lucky ones that won a pair of the new Dayton coaxial CX150-8 5-1/4" drivers at MWAF. So, to fill in the bottom, I picked up a pair of Dayton RS270P-8 10" woofers at the tent sale (got a great deal on these too).






My plan is to build a tower cabinet with a curved left side, using Tom Z's curved cab construction techniques. The side will be laminated from three 1/4" layers of HDF material and then flush trimmed after the glue sets.





Externally, the cab will measure 42" high, 12.5" deep, and average 9.0994" wide. Material will be 3/4" thick, so the internal dimensions will be 40.5" high, 11" deep, and average 7.5994" wide. Gross internal volume will be 1.959 cubic feet, with roughly 0.25 cubic feet used for the midrange and 1.7 cubic feet used for the woofer. See volume calculations in the photo below. Preliminary alignments in WinISD look good for both drivers.

I took some rough prototyping OmniMic & DATS V2 measurements in test boxes and based on this testing, I am fairly certain that my driver selection and layout plan will work. Crossovers will be approximately 400 & 3500Hz at 12dB/octave. Once I get the cabinets roughed out and the drivers mounted, I plan to run up a complete set of on and off axis FRD's to finish the design.

I will post my DATS V2 and low frequency alignment data as soon as I get a chance. When I start building the cabs, I will stop back and post some pics. Feel free to ask questions, comment, or make suggestions as I go along. I have a basic plan, but this is my first attempt at a curved cab. Hopefully I will not mess it up too badly! Wish me luck!

Bill

[6thplanet]

That's going to be a sweet pairing. Any thoughts about OB on the coax?

[TN Allen]

Nice ideas. I look forward to watching your projecy progress and reading your conclusions.

[4thtry]

That's going to be a sweet pairing. Any thoughts about OB on the coax?

This is probably something that I should consider. I really need to get up to speed on OB software packages. Any suggestions for someone that does not use excel?

My sealed 1/4 cu ft box should give me a Qtc of about .6 (half way between critically damped and maximally flat).

[scottvalentin]

Very nice curves on that cabinet - look forward to following this build.

[6thplanet]

Honestly I've never used any software, I'm a build it and play with it type. Put it on a baffle and let your ears and OmniMic tell the tale. Cardboard is your friend 😀

[jhollander]

If you narrow up the baffle to 7.5 inches for the mid you could maintain constant directivity with an x-o point of 2K. With the narrow baffle the RS270 would need to reach up to about 500 Hz or higher. I'd build it.

[4thtry]

If you narrow up the baffle to 7.5 inches for the mid you could maintain constant directivity with an x-o point of 2K. With the narrow baffle the RS270 would need to reach up to about 500 Hz or higher. I'd build it.

John,

Could you expand a little on this. I am totally lost as to what you are suggesting.

[TN Allen]

Has anyone listened to these CX150-08 yet. I'm curious about the bass. The data sheet shows a promising response for this driver in a vented box.

[4thtry]

I've listened to just the woofer portion for about 10 to 15 minutes or so with no cabinet. Seems very robust for a small 5.25 incher. I then broke the driver in with a 25Hz sine wave, running the cone out to about 1/4 inch peak to peak. No strange noises. After 3 hours of this, I let them rest for about 5 minutes and then measured them with DATS V2. So far so good.

[TN Allen]

Sounds promising. Thanks.

[ugly woofer]

Very cool, I really like the curves.

[4thtry]

Very nice curves on that cabinet - look forward to following this build.

Very cool, I really like the curves.

Thanks. I created these curves in photoshop, shaping them with large intersecting arcs. I saved the drawing full scale so I can print it full scale and then attach it to the baffle. My plan is to make the cut slowly by hand with a jig saw.

[tomzarbo]

Bill,
that's going to look pretty cool I think. How do you print out something like that full size? Staples, or go to a surveyor or something like that? Good idea. I end up transferring my computer drawings to full size newspaper print, but it's not as accurate as a full-size printout.

I usually do a full-scale mock-up in cardboard for more curvy cabinets or those with lots of angles to make sure it looks right full size. I've had my sketches look good as sketches but not so good in the flesh until I adjusted a few dimensions. Man, you're not letting the dust settle are you?

Also, I'm pretty sure I landed 4 or 6 of those same terminal cups for like a buck or so each at the tent sale? Yeah, I had to buy them too!

TomZ

[JavadS]

Looking like a fun build Bill! Javad